An isotopic palaeoenvironmental study of human skeletal remains from the Nile Valley

Stable isotope measurements were carried out on human skeletal remains from the Nile Valley, ranging in age from about 7000 to 1750 yr B.P. and on a set of other samples among which are archaeological food remains. Bone samples were analyzed for δ 18O(PO 3− 4), δ 18O(CO 2− 3) and δ 13C(CO − 3) of carbonate hydroxylapatite and δ 13C and δ 15N of collagen. Food remains and tissue samples were analyzed for their δ 13C and δ 15N values. The isotopic composition of bone collagen, apatite and food remains (partially representative of the diet in ancient Egypt) suggest a mixed diet including C 3 plant food and, probably, animal resources (both fresh-water fish and C 3 animals). A rather surprising observation is the lack of differences between isotopic composition of remains of different social classes spanning from the very poor village of Gebelein to the middle class of the rich town of Asyut to the distinguished people who underwent mummification processes after their death. From the palaeoclimatological point of view, the δ 18O(PO 3− 4) values, ranging from 20.6 to 24.5‰, seem to reflect the isotopic composition of Nile river water (also related to relative humidity) rather than real climatic (temperature) variations through time. The oxygen isotope compositions of carbonate and phosphate of the same samples (from 30.2 to 32.5 and from 20.6 to 22.2, respectively) suggest isotopic equilibrium conditions, thus confirming the possibility of also using the carbonate measurements for palaeoclimatological studies, at least in the case of recent and well preserved samples.